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davetoff

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About davetoff

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  • Name
    David
  • Car
    Lotus Turbo Esprit 1981
  • Location
    Farnham

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  1. It's been a while since I've revisited the Esprit, I've been trying to get some additional finances together to pay for the engine rebuild. When the sun comes out it seems to motivate me to do things, so I striped the engine down to constituent parts and tried to catalog everything by taking pictures, although my iphone seems to lose pictures all the time, what is with that! Anyhow all the castings were sent off to get vapour blasted and have returned shiny like new, a thing of beauty I can tell you. The Main casting has been sent to the machine shop to get Hone bored to take the +0.015"/-0.02" engine bearings which were the only ones available. Unfortunately this block was one of the 100 to 1 blocks that was rebored to +0.015", and subsequently a right pain in the **** to get bearings for! The crank also needs to be reground from -0.01" to -0.02" and then be balanced, with the flywheel, its fixings, the cam belt pulley wheel and washer. At the same time I've given the machine shop the new series 4 ball bearing for the spigot shaft on the transmission to put in the crank shaft. I've also given the pistons to the machine shop to clean up for me, along with the Cylinder head, which I asked to be bolted onto the block whilst it was machined, it gives the block added rigidity that can only help. Now just awaiting the return of this so I can get on with the rebuild. Update to follow, hopefully shortly..... So now I have the block back and the pistons, crank and flywheel plus all the periphery that went along with it, I can crack on with the assembly. Yay! I don't know if any of you have had this problem but it is a right b*gger to get the dry sump off the main block. It's tightened down with 10 x M12 nuts and about 10 x M6 nuts, and once released will come off with a beating from a dead blow hammer......usually! But not this time. I gave up after about an hour and decided to put the little grey cells to use rather than my rather aching muscles. I've now come up with a spreader which I have manufactured using the ends of the casting and 4 M10 bolts to pries them apart. Pictures will be coming shortly.....if it works. And it does....sort of! So after being partially defeated by the main casting I thought I would put together the pistons, how hard can this be! I seem to be thwarted at every turn at the moment. In the manual it clearly states that the gudgeon pin is a finger push fit, well I defy anyone who can push these gudgeons in with their fingers! They came out of the pistons, albeit with a bit of persuasion . I measured the internal diameter of the piston 24.1mm and the outside of the gudgeon at 24.5mm so I suspect that the internal diameter of the piston has bulged a bit. Will be taking it back to the machine shop to get a little bit of material removed and I'll get them to check and assemble them too. All in all a fairly unsuccessful foray into engine building! Will try harder next time! Some small successes this weekend, the spreader tool worked to a degree, I managed to separate it to a point then tried to pull it apart with my hands. That thing was trapped, can pull it up 5mm one end then go to the other a pull that up 5mm too, only to have the first end drop by 10mm. Got a bit frustrating I can tell you. In the end I resorted to getting two car jacks at both ends and separated it that way! on another note, had the machine shop clean the engine block after machining but there's still swarf and grit in there so I'm going to have to clean the whole block myself, hate that job with a passion ?. Still at least I'll be able to trial out my new parts washer!
  2. The usual suspects.....most from Lotusbits and SJ's but also Kemp.... Fixings from Margnor and Co-ord Sport, carb kits from Dellorto If you want any further information then I'll be happy to help where I can. I'm still in the process of rebuilding so don't know all the answers! D
  3. Hi Roland, I'm in the process of rebuilding my 910 engine which is similar to the 907, with the difference to the cylinder head valves and dry sump. Both more expensive on the 910 engine because the exhaust valves and oil pump are difficult to get hold of. The spend at the moment is around £2500 for parts and I'll probably have to spend another £2000 for machining on the head and block and the additional parts for the head. I've already rebuilt the carbs myself, an easy job, well worth doing yourself for around £100 for the rebuild kit plus a bit more if you want to get the castings vapour blasted. The rebuild includes forged pistons and HTD pulley, light weight flywheel etc but no SS exhaust, light weight steel cam buckets or polishing and porting. So all in all the main expense comes from buying parts? Hope this helps a little? Cheers David
  4. Hi All, I've just picked up Dave's email regarding this register, great idea, would have added mine earlier if I'd been been on the ball! ? Chassis no: 1079 first reg: 25/08/81 Original colour: gold Current colour: Black interior : Cream Original wheels: BBS Roof stereo: Not sure (after market sunroof installed) Point of interest: Under restoration cheers David
  5. Only an in-reference that there are very few exhaust valves available, this could be because Lotus made very few, or because they are "chewed up" by the turbo engine. However I'm reaching into the recesses of my memory to a previous forum topic that stated that these are rare because of their delicate nature. Either way there aren't many of them about which is what I would like to correct. Happy to be proved wrong and there are millions lying about that I can pick up cheaply (-: Gary hasn't any in stock at present, he has them made, but hasn't replenished his stock....again he is selling them at £65 but with an additional 6 week lead time.
  6. Hi, I'm having to replace the exhaust valves (and the inlet valves) on the head of my Lotus 910 engine. Unfortunately because of the inherent issue with the 910 engine munching exhaust valves like they are going out of fashion, they are now going out of fashion. As such they are a rare and valuable commodity, looking at SJ and Lotusbits they are retailing for around £65 each and as I have to replace 8 of them this isn't a cheap option. Looking around there seems to be nothing similar, however I can get some made, but from Inconel instead of the sodium filled originals. Now for the questions: Has anyone on this forum done this conversion, or does anyone have intimate knowledge of this material and the use of it in these engines? Alternatively does anyone know of the sort of temperatures that this exhaust valve would see so that I can research the material properties myself. And lastly if after all this research would anyone be interested in some for themselves? Not sure of the quantities yet and so the price, but I reckon that we would see a reduction in price to around £30 each. Cheers David
  7. Sorry if I'm stating the obvious, but is there a sufficient air gap between your heat shield and your mount? If not then all that's happening is the heat shield is conducting heat into the mount, rather than diffusing it.
  8. Just thought I'd add my twopence here, I find the best thing to diagnosing the problem is start with easy things like, checking if the alternator is charging your battery. You can do this by placing a voltage meter over the terminals of the battery and if it's around 14v then all is well with it, if less then the alternator needs attention. Next check oil level, is there too much/ too little. The maybe concentrate on coil. But imho I think it sounds like the battery, low voltage causes, fluctuating revs at idle, and consequently the other symptoms you are having. Volt meter on dash is not very reliable, I find it seems to give an approximation rather than the actual voltage. Surprised that the breakdown guy didn't check this though? Good luck though, it doesn't sound too serous, just very annoying.
  9. In the beginning there was light and all was good....... Well up until the point when I removed the cam belt to change it for a nice shiny new one. The crankshaft went clunk, dunk, thug, thought that was a little strange, pretty sure it shouldn't be making that noise )-: My heart sank as I suddenly saw money oozing from the galleries and seals of the engine. When I had stopped crying I decided that action would really need to be taken and find out what needs to be done. I checked the endfloat and it was about 4mm, when it should be 0.08-0.2mm..... so err slightly off. I Knew that the thrust washers had come off, but thought that even with them out this was a little excessive. Initial plan would be to see what was lurking under the dry sump and make a decision from there. So I started stripping off all the ancillaries that I had so lovingly put on just days before. Well at least it was all nice and clean and the bolts weren't rusty and seized, so didn't take too long to remove the plenum and carbs. Even with only those off I felt like I was making immediate progress. Noticed that even though the carbs were cleaned and polished the aluminum had already started to have white corrosion marks on, not good, I'll have to address that when I reinstall. As it was getting cold and late I thought I'd call it a day and attack the engine in the morning. Over night I had been thinking more about it, and realising there and then that this wasn't going to be a quick job, decided to take the engine indoors to my workshop where I can work on it in relative warmth and most importantly the dry, over the winter. This was no mean feat as I had to juggle about a lot of stuff in order to make enough working room around the engine. Why is it that there's never enough storage space? Engine now in the dry I could attack it with zeal, external oil pump was first to go, with about 8 x M6 nuts holding it on, no problem at all, I suppose that all that oil had kept all the nuts nicely protected and lubricated. Very elaborate seal underneath though, it'll have to be an original seal to replace it as I don't fancy cutting that out of the gasket paper. On later internal inspection I found that the annulus and rotor were all good, this was a major plus as these parts are really really rare to get hold of. Whipped the engine over and WD-40'd all fixings that I could see, then went for a cuppa tea. Refreshed and bolts readily soaked, started removing the lower ones on the sump, working my way from the centre outwards, some where extremely tough to get going....a bigger lever was needed. Then removed the smaller nuts around the edge of the casting, these were a b*gger because the casting itself wraps around the nut so tightly that you can only just get a socket on only half the top of the nut. There wasn't a hope in hell of getting any spanner on it either. Felt like this could have been the turning point for me, if I'd struggled too much and either stripped the threads or the outer edges, I'd probably had thrown my tools down in a strop and paid someone to finish the job for me. End seals were then removed, well partly, the cam belt end wasn't going to come off without a special tool that I'd have to make up, so I let it dangle there in the mean time and proceeded onwards. Narrowly escaping the major strop and excessive output of cashflow paying someone to do this engine rebuild for me, I got all the nuts off. Now for teasing the aluminum casting off the long studs, which all in all took about 1 hour. Rubber mallet and casting now severely beaten into submission and with the lower half of the crank casing on the work bench, I inspected the innards like a surgeon and he's poorly patient. As suspected the thrust washers had indeed come out, but were whole, thought they may have been mushed into a billion pieces, good sign. But then there was this additional ring that had been broken, pretty sure that that wasn't supposed to be there. Later investigation on the LF and eyeing it up against the crank in the daylight showed that is was part of the casting of the crankshaft, which had cracked in a perfect circle around the main bearing. Cause was that the number 5 main bearing wasn't getting enough oil from the reworked chamfer on the crank case casting. The PO didn't line up the Vee with the Chamfer so it was starved of all oil, not good for something that was rotating that quickly against another metal object. Took the parts and engine up to Lotusbits for an expert assessment and advice. Although I knew the crank was toast, I thought that the rest would be ok to put back, considering the pistons were new and beautifully forged. However there was a large amount of float on the pins in the piston, so a new set of Mahle forged pistons were purchased along with seal set and rings. looks like this is turning into a full rebuild /-: Have to keep reminding myself that this is a preservation project to keep our heritage on the road. It turns out that the dry sump that I have is the 1 in 100 that was bored out to 0.015", which generally means that because the main bearings are as rare as hens teeth that the sump is now a lovely oily door stop. Only two options available to me: 1. Buy a wet sump engine. or 2. Skim the top off the original lower crank casing and line bore back to standard with a 2nd hand upper casting already at standard size. I wasn't liking any of these options, first one would not only take a vast amount of money out of my pocket it would also depreciate the dry sump engine car. So like most OCD Lotus Esprit drivers I started trawling the internet adamant that I could get the holy grail of bearings to fit my car. By hook or by crook I will find some til my dying day!!!!!!!!! Update to this.... Amazing I found some bearings +0.015" ....yay!!!! I got a mate to send them to me ....yay!!!! Haven't received them yet and this is 3 days after being posted 1st class .....boo!!!!! I'm now quietly crying in the corner of my house while I write this ? Fingers are still crossed that they turn up, could be the Black Friday post is a little slow this week.... Update to the Update Bearings have now turned up, they were sat safe and sound in the post office waiting for collection, only problem was that they didn't tell me they were there!! Good old PO, anyway I nearly keeled over when I opened the box and saw the gleaming bearings glinting in the sunshine. My daughter thought I'd gone a little loopy when I started doing a little jig on the pavement. However she benefited from my unusually generous behaviour by receiving a big chocolate bar from the newsagents. My happiness was alas short lived though, when one of the really really rare bearings, as opposed to the really rare bearings, was scuffed.....oh man, from ecstasy to misery in a few short minutes. I'm not sure I can take this sort of feeling, my constitution isn't used to these roller coaster emotions. Phoning back Phil, who I'd originally bought the bearings from bared no fruit, apart from a sharp discussion about not wanting to return the money to me for supplying a faulty bearing. Eventually all was sorted and my task for looking for another one started out in earnest. Thanks to this forum and in particular JerryS for pointing me in the right direction it turns out these bearings weren't as rare as I was led to believe, apparently they were still available at source, so I got them to send another one through. It just goes to show that when someone gives you advice on something, it's sometimes worth doing the donkey work to find out for yourself! Next installment will be the building of the engine which I will start a new blog for....... One last note, a friend of mine keeps reminding me that so many people generally give up on their restoration, for the very same reason, too much stress and emotional turmoil that it's difficult to take on a constant basis. I think everything had gone so well for me up to this point I'd fooled myself into thinking it would continue on this vein, and when it went a little south, I began to wobble slightly. I feel I'm now over a hurdle and stronger for it.....bring it on!
  10. No you don't have to exchange it.
  11. The chamfer on the casting should overlap the V on the bearing so that oil can run onto the inside of the bearing. I'm at work at the moment, but I can take a picture of the block this evening to highlight what I mean. Lotusbits do a -0.01" crank for around £200, does anyone know of anyone else who is selling these?
  12. Yep it's all very odd. Looking at the main bearing (5) the one with the V groove, I think this failed as the 'V' wasn't lined up with the filed chamfer on the block. Therefore failing due to lack of oil, this in turn popped the thrust bearings out and then the crank started to grind against the case where the ring of the crankshaft casting failed. Just so happens that it was a perfect circle, maybe a crack in the original casting, or possibly a very bad repair, I suspect we'll never know now. Thanks to all you guys out there who helped diagnose the issue and for putting your views across. David
  13. I found out where it comes from, it looks like it's part of the casting around the rear main bearing area. Must either be a weak spot in the casting as it cracked very neatly around the circumference! @Ian worryingly I think you may have been close to the truth!
  14. Thanks Giorgio for the picture and info. I'll have to recreate that tool when I get the time, which at the moment seems like a long way off!!!
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